Thunderstorms- Thunderstorms are the most common types of storms and are usually following tornadoes and hurricanes. The cause of the formation of a storm is the convective current. In the form of a tornado, the heated air rises because the heavier cooler air pushes it upwards. The air begins to cool and expand while it rises. Water vapour in the air cools and condenses to become water droplets. This process goes on for a expanded period of time and a large thundercloud forms high up in the sky. Friction is created and electric discharges are set-off, resulting into lightning because of the activity of the air currents moving upward. The air continues to cool down, powerful winds start to blow and rain begins to fall because the drops become to heavy to be supported in the cloud. To put it simply, the cloud is a bowl and because of the water cycle and evaporation the bowl fills with water and eventually overflows resulting in rain. Thunder-Lightning is very hot, it can be 30 000 - 50 000 degrees F. When it hits the air around it, to such an extreme, the air rapidly expands sending out a vibration or shock wave we hear as an explosion. Lightning- The sky is filled with electric charges and in a calm sky the positive and negative charges are evenly spaced. When there is a thunderstorm they are spread out differently. Ice crystals and hailstones make up a thunderstorm. Ice crystals have a positive charge and hailstones have a negative charge. Ice crystals are pushed to the top of a thunderstorm cloud by an updraft. While this happening, the hailstones are being pushed down in the thunderstorm by its downdraft. These processes separate the positive from the negative charges of the cloud into two levels, the positive charge at the top and the negative at the bottom. When there is a thunderstorm the Earth’s surface has a positive charge. The negative charge at the bottom of the thunder cloud wants to link up with the Earth’s positive charge. A stream of negative charge hurries toward the Earth once the negative charge at the bottom of cloud gets large enough. This is known as a stepped leader and the positive charges of the Earth are attracted to it, so a current of positive charge moves into the air. A strong electric current carries positive charge up into the cloud when the stepped leader and the positive charge from the Earth meet. This electric current is what we as humans see as lightning but is known as the return stroke.
How tornado’s are formed: Tornado’s are still not completely understood by scientist’s. They usually form in giants rotating thunderstorms called supercells. Supercells are formed when cold polar airs, meet warm tropical airs. The result of the two coming together is a great instability caused by the rising warm air. A narrow line of cumulonimbus form which then give birth to that tornado. Lightning storms, heavy rain and hail begin to fall then shortly after the most recognizable part of the tornado begins to descend from the base of the cloud. In actuality the pressure inside the cloud drops due to increasing wind speeds. As the pressure in the tornado drops the air becomes more condense, this continues down the spiral, which gives it the famous funnel shape. In addition to the shape, it also has a hissing sound which turns into a loud roar when it finally reaches the earth. One of the most dangerous elements of a tornado is that if it reaches the ground it will throw around deadly debris. Also there are such things as “invisible tornado's” which are relatively the same, except for the fact that the funnel does not descend down from the base of the clouds. Tornado’s also change their colour based on the soil they’re in contact with, for example, in southern parts of the united states the soil is red which give the tornado a much darker appearance.
1. Clouds form when heat from the sun causes water from ice, oceans, lakes and the ground into a state of evaporation. 2. This water-vapor then rises in parcels or “pockets” of warm air; as the this parcel rises it begins to cool.
3. As the air parcel reaches a higher level where the pressure is lower, it expands and cools because the particles lose energy as they get farther apart.
4. The water vapour in the parcel cools along with it, until the point that it condenses, forming clouds.
<2. ingredients of clouds> To form clouds, it requires 3 key atmospheric ingredients: water, dust particles, and temperature or pressure changes. Water vapor in the air cannot be seen unless it collects and condenses to form cloud. When you see a cloud, it is moisture you are seeing. Clean air will not produce clouds. We need to put a lot of dust into the atmosphere to form clouds. This dust comes form sources such as volcanoes, cars, sea spray form ocean, and fires.When the temperature or pressures decreases, the air cannot hold as much water. The lower the temperature, the greater the condensation of gaseous water to liquid water. <3.different kinds of clouds.>
High clouds ...
Cirrus clouds are ice clouds. They can look like delicate white feathers or streamers. They are always more than three miles up where the temperature is below freezing, even in summer. Wind currents twist and spread the ice crystals into wispy strands.
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Mid-level Clouds ...
Cumulus clouds are the fluffy, white cotton ball or cauliflower-looking clouds with sharp outlines. They are "fair weather clouds" and they are fun to watch as they grow and change in shape and size. Cumulus clouds make beautiful sunsets.
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Altocumulus clouds have white or gray patches or layers, and seem to be made up of round shapes. They are lower than cirrus clouds, but still quite high. They are made of liquid water, but seldom make rain.
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Low-level Clouds ...
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Stratus clouds often look like thin, white sheets covering the whole sky. Since they are so thin, they seldom produce much rain or snow. Sometimes, in the mountains or hills, these clouds appear to be fog.
Clouds of Vertical Development
Cumulonimbus clouds are a sure sign of bad weather to come--at least bad if you don't like rain and hail! These clouds grow on hot days when warm, wet air rises very high into the sky. Up and down winds within the cloud may push water droplets up to very cold parts of the atmosphere, where they freeze. When the ice drops come back down, they get another coating of water and are pushed back up to freeze again. Finally, they get too heavy to stay in the cloud and fall to the Earth as hail stones.
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How does cold air affect weather? Warm air? What are these large groups of air called?
cold fronts
-A cold front's location is at the leading edge of the temperature drop off, which in an isotherm analysis would show up as the leading edge of the isotherm gradient, and it normally lies within a sharp surface trough. Cold fronts can move up to twice as fast as warm fronts and can produce sharper changes in weather.
Development of cold front
Cold fronts are very often associated with a warm front, squall line, or other weather front. Very commonly, cold fronts have an adjacent warm front that is ahead of the cold front. This is known as an occluded front. This forms an area where warm air is occurring and interacting with the cold front, an area known as a warm sector. In the warm sector, severe thunderstorms, tornadoes, and hailstorms are a common occurrence, due to the sharp difference between the warm air that is associated with the warm front and the cold air that is associated with the cold front. A cold front is con Occluded cyclone example. The triple point is the intersection of the cold, warm, and occluded fronts. sidered a warm front if it retreats, and called a stationary front if it stalls.
Fig. 1. Symbols used on weather maps to indicate fronts.
warm fronts Warm fronts are at the leading edge of a homogeneous warm air mass, which is located on the equatorward edge of the gradient in isotherms, and lie within broader troughs of low pressure than cold fronts. A warm front moves more slowly than the cold front which usually follows because colddifferences air is denser and harder to remove from the Earth's surface.__[2]__ This also forces temperature across warm fronts to be broader in scale. Clouds ahead of the warm front are mostly__stratiform__, and rainfall gradually increases as the front approaches.__Fog__ can also occur preceding a warm frontal passage. Clearing and warming is usually rapid after frontal passage. If the warm air mass is unstable, thunderstorms may be embedded among the stratiform clouds ahead of the front, and after frontal passage thundershowers may continue. On weather ss, the surface location of a warm front is marked with a red line of semicircles pointing in the direction of travel
what happens when cold and warm front meat.. Cold air can affect the weather in many way such as if a cold front meats a warm front and the cold air can form a vary bad storm or tornado . when cold and warm front meat they make the air muggy and damp this can form funnel clouds.
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Division of the atmosphere
Divisions of the Atmosphere:
The atmosphere consists of four distinct layers surrounding the earth for a depth of many hundreds of miles. They are, in ascending order, the troposphere, the stratosphere, the mesosphere and the thermosphere.
The Troposphere: This is the lowest layer of the atmosphere and varies in height in different parts of the world from roughly 28,000 feet above sea level at the poles to 54,000 feet at the equator. Within the troposphere, the pressure, density and temperature all decrease rapidly with height. Most of the “weather” occurs in the troposphere because of the presence of water vapor and strong vertical currents produced by the radiation of the sun’s rays from the earth’s surface. In the upper regions of the troposphere, very strong, fast moving and complex winds occur called jet streams. The top layer of the troposphere is known as the tropopause.
The Stratosphere: For a distance of about 50,000 feet above the tropopause, there is a layer known as the stratosphere in which the pressure continues to decrease but in which the temperature
-5- Glossary
Warm front-A front can best be described as the border between two different air masses. A warm front is the leading edge of a milder or warmer air mass. A warm front travels in such a way that it results in warm air replacing colder air. This happens as the warm air rises up and over the cold air below. As the warm air travels upwards, it begins to mix with the cold air aloft and condenses to form clouds. You can usually expect periods of rain or drizzle for many hours as the front approaches.
Trough
An elongated area of low pressure.
Low Pressure Centre
Indicates an area of low atmospheric pressure. In a low, air is flowing counterclockwise into the centre of the Low. The air will rise and cool often resulting in clouds and precipitation.
High Pressure Centre
Indicates an area of high pressure. In a high, air will slowly descend and flow out in a clockwise direction at the ground. Normally a high will bring mainly sunny skies to an area.
Ridge
Defined as an extended area of fairly high atmospheric pressure.
Cold Front
A cold front is the leading edge of colder air. In front of it, you usually have warmer, more humid air. Behind the front lies much cooler or colder and drier air. The cause for cold fronts is colder air masses migrating southward from the polar regions. It is part of the world's natural energy circulation or cycle, this is how the earth "balances" out the warm and cold air masses around the earth.
Lightning
Lightning is a discharge of electricity that occurs in mature thunderstorms. It always precedes thunder because lightning causes thunder. The lightning stroke momentarily heats the air it passes through to an incredibly high temperature. It can heat the air to 30-thousand degrees Celsius. The rapidly expanding air produces a sound called thunder. Along with the lightening and thunder, severe thunderstorms produce destructive hail, downbursts, and even tornadoes.
Thunder
Skies will be overcast or partly cloudy with the sound of thunder detected, but no precipitation observed.
Temperature
Temperature is the degree of hotness or coldness. Air temperatures are influenced by the local landscape, such as the presence of bodies of water. The air temperature is measured in degrees Celsius and is rounded to the nearest degree. The daytime maximum and nighttime minimum temperatures that a forecaster expects are often expressed as a range. If the forecast issued covers a wide region, the highs and lows are not going to be identical across all areas in that region.
Dewpoint
The dewpoint is a measure of atmospheric moisture. It is the temperature at which air must be cooled in order to reach saturation (assuming that air pressure and moisture content are constant). As the surface of the earth cools at night, warm moist air near the ground is chilled and water vapour in the air condenses into droplets on the grass and other objects. Dew is particularly heavy on clear nights, when the earth cools rapidly. When a blanket of cloud insulates the earth, the cooling rate is slower. The greater the difference between the temperature and the dew point, the drier the air.
Contents
More Resources:
http://www.horton.ednet.ns.ca/staff/webb/science10/units/Weather.html
http://library.thinkquest.org/C0112425/main.htm
http://www.wxdude.com/basics.html
http://science.kennesaw.edu/~mdias/webpage/advanced%20organizers/Meteorology%20Basics%20Lecture.ppt
http://www.theweathernetwork.com/glossary/glossaryindex/?ref=topnav_homepage_glossary
http://www.ec.gc.ca/Publications/default.asp?lang=En
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Extreme weathers
Thunderstorms- Thunderstorms are the most common types of storms and are usually following tornadoes and hurricanes. The cause of the formation of a storm is the convective current. In the form of a tornado, the heated air rises because the heavier cooler air pushes it upwards. The air begins to cool and expand while it rises.
Water vapour in the air cools and condenses to become water droplets. This process goes on for a expanded period of time and a large thundercloud forms high up in the sky. Friction is created and electric discharges are set-off, resulting into lightning because of the activity of the air currents moving upward. The air continues to cool down, powerful winds start to blow and rain begins to fall because the drops become to heavy to be supported in the cloud. To put it simply, the cloud is a bowl and because of the water cycle and evaporation the bowl fills with water and eventually overflows resulting in rain.
Thunder-Lightning is very hot, it can be 30 000 - 50 000 degrees F. When it hits the air around it, to such an extreme, the air rapidly expands sending out a vibration or shock wave we hear as an explosion.
Lightning- The sky is filled with electric charges and in a calm sky the positive and negative charges are evenly spaced. When there is a thunderstorm they are spread out differently. Ice crystals and hailstones make up a thunderstorm. Ice crystals have a positive charge and hailstones have a negative charge. Ice crystals are pushed to the top of a thunderstorm cloud by an updraft. While this happening, the hailstones are being pushed down in the thunderstorm by its downdraft. These processes separate the positive from the negative charges of the cloud into two levels, the positive charge at the top and the negative at the bottom. When there is a thunderstorm the Earth’s surface has a positive charge. The negative charge at the bottom of the thunder cloud wants to link up with the Earth’s positive charge. A stream of negative charge hurries toward the Earth once the negative charge at the bottom of cloud gets large enough. This is known as a stepped leader and the positive charges of the Earth are attracted to it, so a current of positive charge moves into the air. A strong electric current carries positive charge up into the cloud when the stepped leader and the positive charge from the Earth meet. This electric current is what we as humans see as lightning but is known as the return stroke.
http://www.youtube.com/watch?v=kEUXr6FMtWk
How tornado’s are formed:
Tornado’s are still not completely understood by scientist’s. They usually form in giants rotating thunderstorms called supercells. Supercells are formed when cold polar airs, meet warm tropical airs. The result of the two coming together is a great instability caused by the rising warm air. A narrow line of cumulonimbus form which then give birth to that tornado. Lightning storms, heavy rain and hail begin to fall then shortly after the most recognizable part of the tornado begins to descend from the base of the cloud. In actuality the pressure inside the cloud drops due to increasing wind speeds. As the pressure in the tornado drops the air becomes more condense, this continues down the spiral, which gives it the famous funnel shape. In addition to the shape, it also has a hissing sound which turns into a loud roar when it finally reaches the earth. One of the most dangerous elements of a tornado is that if it reaches the ground it will throw around deadly debris. Also there are such things as “invisible tornado's” which are relatively the same, except for the fact that the funnel does not descend down from the base of the clouds. Tornado’s also change their colour based on the soil they’re in contact with, for example, in southern parts of the united states the soil is red which give the tornado a much darker appearance.
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Cloud
<1. How do clouds form?>
__http://www.youtube.com/watch?v=CFKOw50dDZY&playnext=1&list=PLC1D76A0052117AF1&index=3__
1. Clouds form when heat from the sun causes water from ice, oceans, lakes and the ground into a state of evaporation. 2. This water-vapor then rises in parcels or “pockets” of warm air; as the this parcel rises it begins to cool.
3. As the air parcel reaches a higher level where the pressure is lower, it expands and cools because the particles lose energy as they get farther apart.
4. The water vapour in the parcel cools along with it, until the point that it condenses, forming clouds.
<2. ingredients of clouds>
To form clouds, it requires 3 key atmospheric ingredients: water, dust particles, and temperature or pressure changes. Water vapor in the air cannot be seen unless it collects and condenses to form cloud. When you see a cloud, it is moisture you are seeing. Clean air will not produce clouds. We need to put a lot of dust into the atmosphere to form clouds. This dust comes form sources such as volcanoes, cars, sea spray form ocean, and fires.When the temperature or pressures decreases, the air cannot hold as much water. The lower the temperature, the greater the condensation of gaseous water to liquid water.
<3.different kinds of clouds.>
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How does cold air affect weather? Warm air? What are these large groups of air called?
cold fronts
-A cold front's location is at the leading edge of the temperature drop off, which in an isotherm analysis would show up as the leading edge of the isotherm gradient, and it normally lies within a sharp surface trough. Cold fronts can move up to twice as fast as warm fronts and can produce sharper changes in weather.
Development of cold front
Cold fronts are very often associated with a warm front, squall line, or other weather front. Very commonly, cold fronts have an adjacent warm front that is ahead of the cold front. This is known as an occluded front. This forms an area where warm air is occurring and interacting with the cold front, an area known as a warm sector. In the warm sector, severe thunderstorms, tornadoes, and hailstorms are a common occurrence, due to the sharp difference between the warm air that is associated with the warm front and the cold air that is associated with the cold front. A cold front is conOccluded cyclone example. The triple point is the intersection of the cold, warm, and occluded fronts.
sidered a warm front if it retreats, and called a stationary front if it stalls.
Read more: __weather fronts - Warm front, Cold front, Occluded front, Fig. 1., Fig. 2., Meteorology today, Basic meteorology__ __http://science.jrank.org/pages/48263/weather-fronts.html#ixzz16sMHwIaD__
warm fronts
Warm fronts are at the leading edge of a homogeneous warm air mass, which is located on the equatorward edge of the gradient in isotherms, and lie within broader troughs of low pressure than cold fronts. A warm front moves more slowly than the cold front which usually follows because colddifferences air is denser and harder to remove from the Earth's surface.__[2]__ This also forces temperature across warm fronts to be broader in scale. Clouds ahead of the warm front are mostly __stratiform__, and rainfall gradually increases as the front approaches. __Fog__ can also occur preceding a warm frontal passage. Clearing and warming is usually rapid after frontal passage. If the warm air mass is unstable, thunderstorms may be embedded among the stratiform clouds ahead of the front, and after frontal passage thundershowers may continue. On weather ss, the surface location of a warm front is marked with a red line of semicircles pointing in the direction of travel
what happens when cold and warm front meat..
Cold air can affect the weather in many way such as if a cold front meats a warm front and the cold air can form a vary bad storm or tornado . when cold and warm front meat they make the air muggy and damp this can form funnel clouds.
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Division of the atmosphere
Divisions of the Atmosphere:
The atmosphere consists of four distinct layers surrounding the earth for a depth of many hundreds of miles. They are, in ascending order, the troposphere, the stratosphere, the mesosphere and the thermosphere.
The Troposphere:
This is the lowest layer of the atmosphere and varies in height in different parts of the world from roughly 28,000 feet above sea level at the poles to 54,000 feet at the equator. Within the troposphere, the pressure, density and temperature all decrease rapidly with height. Most of the “weather” occurs in the troposphere because of the presence of water vapor and strong vertical currents produced by the radiation of the sun’s rays from the earth’s surface. In the upper regions of the troposphere, very strong, fast moving and complex winds occur called jet streams. The top layer of the troposphere is known as the tropopause.
The Stratosphere:
For a distance of about 50,000 feet above the tropopause, there is a layer known as the stratosphere in which the pressure continues to decrease but in which the temperature
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Glossary
Warm front -A front can best be described as the border between two different air masses. A warm front is the leading edge of a milder or warmer air mass. A warm front travels in such a way that it results in warm air replacing colder air. This happens as the warm air rises up and over the cold air below. As the warm air travels upwards, it begins to mix with the cold air aloft and condenses to form clouds. You can usually expect periods of rain or drizzle for many hours as the front approaches.
Trough
An elongated area of low pressure.Low Pressure Centre
Indicates an area of low atmospheric pressure. In a low, air is flowing counterclockwise into the centre of the Low. The air will rise and cool often resulting in clouds and precipitation.High Pressure Centre
Indicates an area of high pressure. In a high, air will slowly descend and flow out in a clockwise direction at the ground. Normally a high will bring mainly sunny skies to an area.Ridge
Defined as an extended area of fairly high atmospheric pressure.Cold Front
A cold front is the leading edge of colder air. In front of it, you usually have warmer, more humid air. Behind the front lies much cooler or colder and drier air. The cause for cold fronts is colder air masses migrating southward from the polar regions. It is part of the world's natural energy circulation or cycle, this is how the earth "balances" out the warm and cold air masses around the earth.Lightning
Lightning is a discharge of electricity that occurs in mature thunderstorms. It always precedes thunder because lightning causes thunder. The lightning stroke momentarily heats the air it passes through to an incredibly high temperature. It can heat the air to 30-thousand degrees Celsius. The rapidly expanding air produces a sound called thunder. Along with the lightening and thunder, severe thunderstorms produce destructive hail, downbursts, and even tornadoes.Thunder
Skies will be overcast or partly cloudy with the sound of thunder detected, but no precipitation observed.Temperature
Temperature is the degree of hotness or coldness. Air temperatures are influenced by the local landscape, such as the presence of bodies of water. The air temperature is measured in degrees Celsius and is rounded to the nearest degree. The daytime maximum and nighttime minimum temperatures that a forecaster expects are often expressed as a range. If the forecast issued covers a wide region, the highs and lows are not going to be identical across all areas in that region.Dewpoint
The dewpoint is a measure of atmospheric moisture. It is the temperature at which air must be cooled in order to reach saturation (assuming that air pressure and moisture content are constant). As the surface of the earth cools at night, warm moist air near the ground is chilled and water vapour in the air condenses into droplets on the grass and other objects. Dew is particularly heavy on clear nights, when the earth cools rapidly. When a blanket of cloud insulates the earth, the cooling rate is slower. The greater the difference between the temperature and the dew point, the drier the air.-6-
Work Cited
__http://www.weatherquestions.com/How_do_clouds_form.htm__
__http://www.vivoscuola.it/US/RSIGPP3202/umidita/lezioni/form.htm__
Science p530
__http://weather.about.com/od/cloudsandprecipitation/f/cloudformation.htm__
__http://spaceplace.nasa.gov/en/kids/cloudsat_puz2.shtml__|
__http://www.theweathernetwork.com/index.php?product=glossary&pagecontent=glossaryindex&pagecontent=warmfront__
__weather fronts - Warm front, Cold front, Occluded front, Fig. 1., Fig. 2., Meteorology today, Basic meteorology____http://science.jrank.org/pages/48263/weather-fronts.html#ixzz16sMHwIaD__
Hatheway, Becca. "Lightning Formation." Windows to the Universe. National Earth Science Teachers Association, 27 May 2010. Web. 6 Dec 2010. <http://windows2universe.org/earth/Atmosphere/tstorm
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